[alsa-devel] [PATCH] ASoC: pxa-ssp: make suspend call resilient against multiple invocations

[Daniel Mack]

The suspend callback is called twice when the machine is suspended, once
through the ASoC layer and once through the platform device layer. Make sure
not to confuse the clock layer with unbalanced calls, and bail out early if
we are already suspended.

Signed-off-by: Daniel Mack <daniel at zonque.org>
---
 sound/soc/pxa/pxa-ssp.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/sound/soc/pxa/pxa-ssp.c b/sound/soc/pxa/pxa-ssp.c
index adcf8ba9d287..fd93706702a6 100644
--- a/sound/soc/pxa/pxa-ssp.c
+++ b/sound/soc/pxa/pxa-ssp.c
@@ -51,6 +51,7 @@ struct ssp_priv {
 	uint32_t	cr1;
 	uint32_t	to;
 	uint32_t	psp;
+	bool		suspended;
 #endif
 };
 
@@ -142,6 +143,9 @@ static int pxa_ssp_suspend(struct snd_soc_dai *cpu_dai)
 	struct ssp_priv *priv = snd_soc_dai_get_drvdata(cpu_dai);
 	struct ssp_device *ssp = priv->ssp;
 
+	if (priv->suspended)
+		return 0;
+
 	if (!cpu_dai->active)
 		clk_prepare_enable(ssp->clk);
 
@@ -152,6 +156,8 @@ static int pxa_ssp_suspend(struct snd_soc_dai *cpu_dai)
 
 	pxa_ssp_disable(ssp);
 	clk_disable_unprepare(ssp->clk);
+	priv->suspended = true;
+
 	return 0;
 }
 
@@ -161,6 +167,9 @@ static int pxa_ssp_resume(struct snd_soc_dai *cpu_dai)
 	struct ssp_device *ssp = priv->ssp;
 	uint32_t sssr = SSSR_ROR | SSSR_TUR | SSSR_BCE;
 
+	if (!priv->suspended)
+		return 0;
+
 	clk_prepare_enable(ssp->clk);
 
 	__raw_writel(sssr, ssp->mmio_base + SSSR);
@@ -174,6 +183,8 @@ static int pxa_ssp_resume(struct snd_soc_dai *cpu_dai)
 	else
 		clk_disable_unprepare(ssp->clk);
 
+	priv->suspended = false;
+
 	return 0;
 }
 
-- 
2.17.2